我最近发现onActivityResult已弃用。我们该怎么处理呢?
有什么替代方案吗?
我最近发现onActivityResult已弃用。我们该怎么处理呢?
有什么替代方案吗?
当前回答
我想出了如何从Kotlin的片段中正确地做到这一点,以捕获图像并处理返回的位图。在其他情况下也是一样的。
首先,您必须注册片段以侦听活动结果。这必须在初始化片段之前完成,这意味着创建一个成员变量,而不是在onCreate函数中初始化。
class DummyFragment : Fragment() {
//registering fragment for camera listener
private val takePhoto = registerForActivityResult(
ActivityResultContracts.StartActivityForResult()
) {
if (it.resultCode == Activity.RESULT_OK) {
val imageBitmap = it.data?.extras?.get("data") as Bitmap
// do your thing with the obtained bitmap
}
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
}
然后,像你通常做的那样调用摄像机意图。并使用上面创建的变量来启动意图。
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
someRandomButton.setOnClickListener {
val takePictureIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
takePhoto.launch(takePictureIntent)
}
}
其他回答
在Java 8中,它可以这样写:
ActivityResultLauncher<Intent> startActivityForResult = registerForActivityResult(
new ActivityResultContracts.StartActivityForResult(),
result -> {
if (result.getResultCode() == AppCompatActivity.RESULT_OK) {
Intent data = result.getData();
// ...
}
}
);
Intent intent = new Intent( ... );
startActivityForResult.launch(intent);
您可以为Koltin使用扩展函数。例如:
//random utils file
fun Fragment.buildGetContentRequest(function: (Uri) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetContent()) {
function(it)
}
}
fun Fragment.buildTakePhotoRequest(function: (Boolean) -> Unit): ActivityResultLauncher<Uri> {
return this.registerForActivityResult(ActivityResultContracts.TakePicture()) {
function(it)
}
}
fun Fragment.buildSelectMultipleContentRequest(function: (MutableList<Uri>?) -> Unit): ActivityResultLauncher<String> {
return this.registerForActivityResult(ActivityResultContracts.GetMultipleContents()) {
function(it)
}
}
然后在你的片段中像这样
//your actual fragment logic
class YourFragment : Fragment() {
//we can assign our request in init process
private val mRequestSelectFiles = buildSelectMultipleContentRequest {
onFilesSelected(it)
}
fun onSelectFiles() {
val mime = "*/*"
mRequestSelectFiles.launch(mime)
}
fun onFilesSelected(list: MutableList<Uri>?) {
//your logic
}
}
参考:Kotlin -从图库中选择图像
迄今为止我发现的最简单的Alernative
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.id.activity_main)
var ivPhoto = findViewById<ImageView>(R.id.ivPhoto)
var btnChoosePhoto = findViewById<Button>(R.id.btnChoosePhoto)
val getContent = registerForActivityResult(ActivityResultContracts.GetContent()) { uri: Uri? ->
ivPhoto.setImageURI(uri) // Handle the returned Uri
}
btnChoose.setOnClickListener {
getContent.launch("image/*")
}
}
下面的代码在Kotlin片段中工作,用于检查蓝牙权限。年- 2022年
val intent = intent (BluetoothAdapter.ACTION_REQUEST_ENABLE)
registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
if (result.resultCode == Activity.RESULT_OK) {
// There are no request codes
val data: Intent? = result.data
bluetoothAdapter.enable()
Toast.makeText(context, "Permission Granted: ", Toast.LENGTH_SHORT).show()
dynamicButton()
}
else{Toast.makeText(context, "You have to enable bluetooth to use this app.", Toast.LENGTH_SHORT).show()}
}.launch(intent)
以下是我的解决方案:
在我们的项目中,我们有超过20次的startActivityForResult(和onActivityResult)。
我们希望尽可能少地更改代码(并继续使用请求代码),同时引入一个优雅的解决方案以供将来使用。
既然我们很多开发人员都使用BaseActivity概念——为什么不利用它呢?
下面是BaseActivity:
abstract class BaseActivity : AppCompatActivity()
{
private var requestCode: Int = -1
private var resultHandler: ActivityResultLauncher<Intent>? = null
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
registerForActivityResult()
}
private fun registerForActivityResult()
{
if (shouldRegisterForActivityResult())
{
resultHandler = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
onActivityResult(result.data, requestCode, result.resultCode)
this.requestCode = -1
}
}
}
fun startActivityForResult(requestCode: Int, intent: Intent)
{
this.requestCode = requestCode
resultHandler?.launch(intent)
}
protected open fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
{
// For sub activities
}
protected open fun shouldRegisterForActivityResult(): Boolean
{
// Sub activities that need the onActivityResult "mechanism", should override this and return true
return false
}
}
这是SubActivity:
class SubActivity : BaseActivity()
{
companion object
{
private const val SOME_REQUEST_CODE = 300
}
private fun testActivityResult()
{
val intent = Intent(this, OtherActivity::class.java)
startActivityForResult(SOME_REQUEST_CODE, intent)
}
override fun shouldRegisterForActivityResult(): Boolean
{
return true
}
override fun onActivityResult(data: Intent?, requestCode: Int, resultCode: Int)
{
if (requestCode == SOME_REQUEST_CODE)
{
// Yes!
}
}
}
希望它能帮助到别人